Loosely, "varies inversely" means that as one quantity increases, the other decreases. Specifically, if x and y vary inversely, then y = k/x where k is some constant (a particular number).
Another way to write that relationship is xy = k. To find the value of k for this problem, you need a numbers for x and y that go together.
Suppose x = number of children and y = number of candies (it doesn't matter what order these go in as long as you keep track!).
"When 12 children are present, 140 pieces of candy are consumed." So when x = 12, the value of y = 140.
xy = k
(12)(140) = k
1680 = k
Now, when x = 8 children,
8y = 1680
y = 210
This seems like a lot more work than it is, but here we go
Simplifying<span>8 + -2y = 3y + -2
Reorder the terms: 8 + -2y = -2 + 3y
Solving 8 + -2y = -2 + 3y Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right.
Add '-3y' to each side of the equation. 8 + -2y + -3y = -2 + 3y + -3y Combine like terms: -2y + -3y = -5y 8 + -5y = -2 + 3y + -3y
Combine like terms: 3y + -3y = 0 8 + -5y = -2 + 0 8 + -5y = -2 Add '-8' to each side of the equation. 8 + -8 + -5y = -2 + -8
Combine like terms: 8 + -8 = 0 0 + -5y = -2 + -8 -5y = -2 + -8 Combine like terms: -2 + -8 = -10 -5y = -10
Divide each side by '-5'. y = 2
Simplifying y = 2</span><span>
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